Process of preparing lacquers, varnishes, or the like



Patented July 31, 1934 PRooEss F PREPARING LAoQUERs, VARNISHES, on THELIKE Ernst Elbel and Fritz Seebach, Erkner, near Berlin, Germany,.assignors to Bakelite Gesellschaft mit beschrankter Haftung, Berlin,Ger- ,many

No Drawing. Application January 22, 1930, Serial No. 422,683. In GermanyJanuary 29, 1929 lolaims. (oi. 134-26) I v According to our prior'U, S.application Ser..No. the finished lacquer andconverted into .a resitole,295,344 filed July 25, 1928, lacquers or varnishes and any waterremaining as a result of the convencan be prepared from resit'oles, thatis, synthetic sion that has not been eliminated during the resinousproducts of a hardenable'nature which course of heating the resolesolution can .be re-.

are in an intermediate or E state wherein they are moved by distillationunder normal pressure or a {if} not fusible or soluble but swell in theusual sol partial vacuum. The elimination'oi the waterof vents.Acc'ordingto that disclosure lacquers or reaction is very. important forotherwise the varnishes are obtained by dissolving resitoles invarnishes are likely to exhibit cloudiness and suitable solvents, eitheralone'or with the additroublesome pr p It 13.84180 possible 30' tion ofother resins, under normal atmospheric, proceedas, for instance, byinterrupting the heat& 65

reduced or increased pressure and at ordinary or me, o t a p only of theresole is n te elevated temperatures. It has now been found 11 3 aitupon further investigation that lacquers and var- It is n t es ntial tbe in wi h re l nishes consisting of resitole solutions are obtained Risito Solutions c be Obtained from Home 15 more readily and moreadvantageously in comhardenable condensat o reaction Products, 70.parison with the process disclosed in thefaforethe so-called novolaks,by dissolving t said prior application, according to whichthe s' her wih hardeni agents, such as aldehydes' resitolesare first prepared andthen brought into or their polymer hy ib Substances solution, by causingthe formation of the resitoles as hexamethylenetetmmine, baSicaillyacting in the presence of a greater or less amountof substances asoxides or hydroxides, or other suit- 75 substances that are suitable assolvents. While able metal compounds inappropriate solvents the solventsmentionedin the prior application' and th n beginning t are remarkablygood solvents for resitoles,'their Resole solutions can be heated in theusual solution therein, however, requires'care in avoids ma ne u der edincreased- DYBSSUTE 2s ing overheating the solutions to thereby' causeaoth tu lv r synthetic, hardenable or on-- so partialconversion of: theresitoles into resiteshardenable resins can be added to a solutionbethat is, the final infusible and practically infore, dur after thealing p AS soluble or C products-and consequent precipi- V nts therecan, for example, be used hydrogentation of the resins. According to theprocess of ated phenols, cyclic ketones or the homologs of the presentinvention not only are the lacquers these bodies, besides iuriural.Organic liquids 5.. and varnishes prepared from resoles or harden- Whichhave no solvent power as tetralin or homoable synthetic resins in aninitial fusible and benZol can be employed in admixture with thesesoluble or A condition in one operation but the solvents. Furthermoreone can proceed by adddanger of precipitation through overheating is ingto the solution catalyzers, as nitrophenols,

- 0vercome. which accelerate the hardening of the lacquer 90 Inaccordance with this invention resoles are film- Finally plasticizersand fireproofing comdissolved in suitable amounts of a solvent orsolpounds can be included. Suitable plasticizers, vents and converted tothe resitole form by heatbesides the triamylphosphates mentioned in theing the solution. The greater the amount of solprior application, areoils, chlorinated or hy- 40 vent used the less is the danger ofoverheating the drogenated naphthalenes, etc. 95

' 'resitoles through contact with parts of the appa- One can for exampleproceed as follows:

ratus that are overheated to cause formation of 1. 50 kilos resole aredissolved in 25 kilos cycloinsoluble products. For example, the entirehexanol and heated until the at first thinly liquid amount of solvent tobe used can be added to a substance starts to solidify; then 59 kiloscyclo- -1'esole, as described in the prior application in hexanol areadded and heated until solution is 100 i connection with resitoles, toyield directly resitole completed. The solution is then poured into woodlacquers upon sufiicient heating. The technical alcohol to obtain a thinlacquer.

procedure however is subject to wide variation; 2. 30 parts by weight ofresole are dissolved in the various methods described in the priorappli- 20 parts by weight of cyclohexanol and are heated --cation areadaptable to the present case. Thus at about 110 C. until the resole inthe solution 105 a resole can be dissolved in a greater amount of iscompletely converted into resitole. This is solvent than that requiredfor a varnish and the recognized by the fact that, after approximatelyexcess solvent can be removed from the final to 1 hours heating a livelygas formation sets resitole solution by distillation. Or a resole can inaccompanied by more or less violent foaming.

be dissolved in an amount of solvent desired in The gases and foamingare caused by the water 11:

forming during the conversion or the resoles into resitoles, which doesnot mix with cyclohexanol. The removal of the water may be completed byheating under a partial vacuum or with substances acting as dehydratingagents, such as calcium chloride.

3. 27 parts by weight of novolak and 2.7 parts by weight ofhexamethylenetetramine are dissolved in 20 parts by weight ofcyclohexanol, and the procedure is followed as in Example 2.

The resitole solutions obtained according to Examples 2 and 3 maylikewise be mixed with wood alcohol or other varnish solvents.

The following definitions are intended for the terms resole, resitole,resite and novolak. A resole is a resin of the type hardenable by heatto a final infusible insoluble condition but reacted only to the stagewhere it still melts when heated and is soluble in acetone; this is alsoknown as the A-stage or A condition and the resin at this stage is knownas an A-type resin. A resitole is a resin of the same type as a resolebut further reacted to a B state or B type where it has becomeinfusible, i. e., it does not melt although it softens somewhat uponheating and it is insoluble but swells in acetone. A resite is the sameheat-hardenable resin but reacted to the final or C stage or C product,characterized by complete insolubility in acetone and infusible withoutany material softening upon heating. A novolak is a distinctly differenttype of resinous reaction product in that practically speaking it doesnot harden upon heating to an insoluble infusi'ble condition but remainssoluble and fusible. The resins here defined are those made from thephenols or their derivatives with a methylene or aldehyde agent as iswell understood by those skilled in the art.

We claim:

1. A process of making lacquers and varnishes containing hardenablephenol-formaldehyde resins which comprises dissolving aphenol-formaldehyde resin in the resole stage at which it still meltswhen heated and is soluble in alcohol in a solvent of the groupconsisting of hydrogenated aromatic hydrocarbons, hexahydrogenatedphenols and their esters and hydroaromatic cyclic ketones, heating thesolution at converting temperature until a conversion ofphenol-formaldehyde resin of the resole stage into a phenol-formaldehyderesin of the resitole stage takes place, which resitole is thermoplasticbut infusible and is insoluble in alcohol but swells therein, and addingliquids if necessary to maintain the product fluid.

2. Process of making lacquers and varnishes containing hardenablephenol-formaldehyde resins which comprises dissolving a permanentlysoluble and fusible phenol-formaldehyde resin together with a hardeningagent in a solvent of the group consisting of hydrogenated aromatichydrocarbons, hexahydrogenated phenols and their esters andhydroaromatic cyclic ketones, heating the solution at convertingtemperature until a conversion of fusible resin into aphenolformaldehyde resin which is thermoplastic but infusible and whichis insoluble in alcohol but swells therein takes place, and addingliquids if necessary to maintain the product fluid.

3. A process according to claim 1, characterized therein that organicliquids which do not dissolve phenol-formaldehyde resin of the saidresitole stage are used in conjunction with said solvent.

4. As a, composition of matter a solution of a phenol-formaldehyde resinin an organic solvent of the group consisting of hydrogenated aromatichydrocarbons, hexahydrogenated phenols. and their esters andhydro-aromatic cyclic ketones, which composition is prepared bydissolving in said organic solvent a preformed phenol-formaldehyde resinwhich has been reacted to a stage at which it is thermoplastic andfusible and at which it is soluble in alcohol, and converting said resinto a stage of resinification at which it is thermoplastic but infusibleand at which it is insoluble in alcohol but swells therein by heatingthe so-prepared solution at converting temperature until said conversionhas been effected.

ERNST ELBEL.

FRITZ SEEBACH.

